NC 2009 SSc8: Light Pollution Reduction

Yes, assuming your site boundary is along a "public right-of-way" and not someone else's property. Since you mention "15 feet" I assume you are in LZ3. The language says: "maximum initial illuminance value no greater than 0.20 horizontal and vertical footcandlesVertical footcandles occur on a vertical surface. They can be added together arithmetically when more than 1 source provides light to the same surface. at the site boundary and no greater than 0.01 horizontal footcandlesHorizontal footcandles occur on a horizontal surface. They can be added together arithmetically when more than 1 source provides light to the same surface. 15 feet beyond the site boundary"

So "site boundary" in this case, and for this measurement, is the curb line.

I do not think you need to install shieldingShielding is a nontechnical term that describes devices or techniques that are used as part of a luminaire or lamp to limit glare, light trespass, or sky glow. devices in areas where the option 1 requirements are met. I believe that you can use option 1 or option 2 in different spaces within the same project. Nothing in the credit language prevents this as far as I can tell.

You should explain this in your narrative.

According to LEED Interpretation ID# 5149

"The applicant appears to be requesting clarification for the following questions: [1] can Option 1 and Option 2 of the interior lighting requirements be implemented on a space-by-space basis ... The responses to each of the questions are as follows: [1] The proposed approach is acceptable. Spaces are required to either satisfy interior lighting requirements using Option 1 (i.e., minimize light penetration through opaque surfaces) or Option 2 (i.e., install automatic lighting control)..."

Officially it says, "...cannot be traded between surfaces..." I'm sure many projects have not followed this and reviewers only considered the facade lighting as a single line item.

Don't worry. You get an extra 5% for the entire site that can be used anywhere. That should easily cover a few extra watts on one wall.

Bill,

Not sure I agree with your interpretation. I think when they say in 90.1 table 9.4.5 "cannot be traded between surfaces" they are talking about the various "non-tradeable surfaces" (facades, ATM's, loading areas, etc.) not facade surfaces.

So I think you can develop a total facade lighting power allowance based on the "each illuminated wall or surface" area and then use that allowance across all areas of facade.

I don't think anyone is enforcing it the way I read it. I've just gotten so many Electrical Inspectors that take pride in creative ways to enforce the NEC that I read everything as a worst case interpretation.

Ranting off topic but I've had an Inspector tell me no more than 2 computers on a circuit because the nameplate on the back of the computer and monitor added up to 7A. 3*7 is over 20A. In real life having 6 computers on a circuit is no proplem, but per the letter of the Code the Inspector was right.

Yeah, in one of these versions on this site I quoted a CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide for a dormitory where they said this method would be accepted. Remember to count the visible light transmission of the glass too.

If the lighting is not normally on and will only turn on during an emergency you should be able to exclude it.

If the light is normally on and has an emergency battery or generator back up then the exemption only applys to the closest grid. The one on the property boundary. The grid measured 10-15 beyond must still meet the 0.01 fc1. A footcandle (fc) is a measure of light falling on a given surface. One footcandle is defined as the quantity of light falling on a 1-square-foot area from a 1 candela light source at a distance of 1 foot (which equals 1 lumen per square foot). Footcandles can be measured both horizontally and vertically by a footcandle meter or light meter. 2. The non-metric measurement of lumens per square foot, one footcandle is the amount of light that is received one foot from a light source called a candela, which is based on the light output of a standardized candle. A common range for interior lighting is 10 to 100 footcandles, while exterior daytime levels can range from 100 to over 10,000 footcandles. Footcandles decrease with distance from the light source. The metric equivalent of a foot candle is 10.76 lux, or lumens per square meter. requirement.

"Campus projects can choose whether to comply with the requirements for the building site boundary or to meet the light trespass requirements for the campus as a whole"

Where does this come from? Just checked the Reference Guide and could not see anything pointing towards this?

The only way I can see that a campus boundary can be used is with the AGMBC if this credit is a Master Site credit. However, it is also confusing, since there is a PE requirement for the interior lighting portion of the credit if the campus approach is to be followed. Totally confusing! I thought PE exemptions were only options to be followed at the discretion of the team, here is a case that actually prevents projects from gaining a credit.

I think the reviewer couldn't put 2 and 2 together. They didn't know it was a Master Site. Sounds like an additional step is needed in approval and you need to hold their hand to say this is a "Master Site". Also, all other buildings on the site need to comply with LEED prerequisites. I read thru the latest AGMBC and this part may be of interest to you.

"Campus credits allow eligible LEED credits and prerequisites to be documented once for an entire campus. These campus credits are pre-approved through a separate review in the master site. Once pre-approved, campus credits are available to LEED projects (both individual and group projects) associated with the same master site and located within that same LEED campus boundary.

"The AGMBC Help section of LEED Online v3 contains detailed information to explain how to register and certify projects using this guidance. The Help content should be used alongside this guidance document to certify projects.

"Creating a Master Site
All campus credit information is documented within a master site in LEED Online v3. Projects on the campus that submit for certification and reference the master site can utilize the credits pre-approved in the master site review. When registering a master site in LEED Online, please use the words master site in the title (for example, State University Master Site)."

Bill,

If you are replying to Chern's comment, I am not sure if they have used the campus approach. Since there is only one building in question, maybe they do not have a master site. He is trying to confirm what he has read before - which I replied because I don't think what he has read has any foundation in the reference guide.

My comment also pointed to the fact that the credit cannot even be applied as a Master Site credit if there is no PE taking care of interior lighting on board. This is from the AGMBC v2, which I also think includes some typos:

SSc8 Master Site
"
Exterior: The exterior lighting credit requirements apply to the area within the LEED campus boundary.

Interior: Eligible as a campus credit only when using the Licensed Professional Exemption streamlined path for the interior lighting requirements or all buildings within the LEED Campus Boundary."

Doesnt't this in effect mean that if the licensed professional exemption path is not applied, then the credit cannot be earned on a Master Site basis?

Finally, when you say that all other buildings on the site need to comply with prerequisites, you mean something else I guess? Or does USGBC expect buildings on a Master Site that will not be LEED certified to indeed comply with the prerequisites?

Pir CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide dated 10/16/2008:

The applicant has requested clarification if light trespass thresholds are applicable along parcel property lines within a shared master site or campus. Per the LEED-NC Application Guide for Multiple Buildings and On-Campus Projects (AGMBC), this credit can be attempted at the campus level, negating the need to meet the light trespass thresholds along parcel property lines as long as the requirements are met for the campus as a whole. Please refer to the AGMBC (http://www.usgbc.org/ShowFile.aspx?DocumentID=1097) for additional details on attempting this credit at the campus level.

Update April 15, 2011: Please note that all 2009 projects in multiple building situations must follow the 2010 Application Guide for Multiple Buildings and On-Campus Building Projects, located here: https://www.usgbc.org/ShowFile.aspx?DocumentID=7987. 2009 project teams should check this document for up to date guidance on all multiple building issues.

It sounds like for v2009 projects now we cannot just say we're using a campus approach. We have to register the campus on LEED-Online as a Master Site first and then we can claim the campus credit only after the Master Site earn the credit. Per the instructions for registering a Master Site, one requirement is for all buildings to comply with LEED prerequisites. I don't see how we can apply a campus approach to this credit any more if we can't register the site per AGMBC.

Your quote is coming from Appendix A. The way I read it is they have this credit divided into 2 parts. Exterior and interior. You can apply the campus approach to either or both. If you apply the campus approach for interior lighting then you need the PE to sign off. If you can't do that then just try submitting the interior compliance for this building only and use the campus approach for the exterior portion.

Thank you all for your kindly reply. I am still trying to figure out a way to comply with this credit. Simply because the site boundary I used for this project had been consistent with other credits. I used the master site boundary for compliance in SSC5, SSC7.1 as well, and the parking lots, bicycle racks are all situated within the master site boundary. I don't think I was inconsistent.

Bill,

I don't understand why you are saying "Per the instructions for registering a Master Site, one requirement is for all buildings to comply with LEED prerequisites". Where is this coming from? This is not in the AGMBC.

If this were the case, then wouldn't we have to register each building in the campus so that their prerequisites can be reviewed? Even if they are not being LEED certified?

Thanks.

If someone can correct me that's fine. I'm just reading from the October 2011 version of the AGMBC.
https://www.usgbc.org/ShowFile.aspx?DocumentID=10486
Starting at the bottom of Page 4.
"LEED projects that elect to use this guidance should meet all of the following criteria:
- Certification is being pursued under one of the LEED 2009 rating systems.
- All buildings or spaces are under control of the same owner, developer, or property management.
- All buildings or spaces are located on a single site, as defined in the LEED Minimum Program Requirements.
- Each of the buildings or spaces can independently meet the LEED Minimum Program Requirements. [note that for MPR #6, buildings must individually meter and make available whole building energy and water usage data after certification]
- Each of the buildings or spaces can independently meet all prerequisites of the LEED rating system being used with certain exceptions noted in the credit level guidance."

The last item says "each of the buildings...". Maybe they meant "each of the LEED buildings..." but that's not what they said. I'd love to be wrong about this. If anyone know more about the AGMBC process please comment. The list of information to provide for the Master Site submittal does not include anything about other non-LEED buildings on the site.

Jorng-ren,
I suggest responding to the Reviewer and tell them you are using a campus site boundary to show compliance with this Credit. This is the same boundary as we used in SSc5 and SSc7.1.

That should get you thru this project review. Like I said, I think the Review just didn't realize you were using a campus approach. And they're just checking off boxes on their list of things to review. And one of those boxes is to compare the Credit boundary to the broundary in the Overview Documents.

Breeze, I don't have experience with this, but I can suggest that this would have a good chance of not working, although it may be worth a try, either through a narrative or a CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide.

Reasons it would not work are that LEED 2012 is in draft, not balloted, so you have no official language to draw from, and that there is precedent for requirements to evolve between rating systems version, but not to regressively change past versions.

Again, may be worth a try, though.

Thanks for the reply Tristan. We are submitting a CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide with the language below, and have revised to notate that 2012 is in draft, not ballot. Understanding that the response will not be precedent setting, we will share once we hear back.

"Best to our knowledge, no hospital project has ever achieved this credit under LEED BD+C 2009/ Healthcare due to the interior lighting requirements which are simply unfeasible for any hospital project to implement.

Under LEED BD+C or HC , to achieve the credit as a 24/7 facility, a hospital must follow Option 2, and install 90% black out shades, and a motor tied to a BMS system, at every single exterior window in the project, that automatically lowers the shade from 11pm-5am.

As the hospital is a 24/7 facility and almost any program space has the potential to be in operation 24/7, this requirement will apply to literally every single window in our 521,000 sf building.

This impracticality of this requirement has in fact already been recognized by the USGBC and its balloting body - LEED 2012; 2nd public comment version, allows healthcare projects to exclude all interior lighting requirements. With regards to exterior lighting requirements, our project has been designed to fully meet the LEED for Healthcare version of this credit, which allows certain provisions specific to medical functions such as exemption of the emergency room, etc.

Our project would like to propose the following as a LEED BD+C 2009 registered project;

1. Meet the LEED for Healthcare SSc8 Light Pollution reduction requirements for exterior lighting.
2. Grant an exemption for interior lighting requirements; recognizing that by the time our building is in operation (2016), LEED 2012 will already have granted this provision in subsequent versions.

We believe this will allow the project to meet the overall credit intent of reducing night time light pollution, while providing a feasible path for credit achievement that truly recognizes the 24/7 operation of healthcare facilities."

Breeze,
Sorry if my comment comes too late for your benefit, but the current LEED-NC 2009 Template for SS Credit 8 contains a radio button with the text "Project is a hospital and is exempt from the Interior Lighting requirements."
Seems like that would be reflected in LEED-HC 2009 Template as well. Perhaps all you need is an updated template?

This is an example where this Credit seems to penalize high density urban projects.

I found a way to make it work by lighting the plaza with a pole in the very center of the plaza and still comply with this credit exactly while also providing even lighting in the plaza. But I doubt you want a pole in the middle of your plaza.

Otherwise the best I have is using the Pilot Credit but this will use up one of your ID credits. If you're already using all of the ID credits then Pilot Credits don't help. Most full cutoffA full cutoff luminaire has zero candela intensity at an angle of 90 degrees above the vertical axis (nadir or straight down) and at all angles greater than 90 degrees from straight down. Additionally, the candela per 1,000 lamp lumens does not numerically exceed 100 (10%) at an angle of 80 degrees above nadir. This applies to all lateral angles around the luminaire. wall packs will have a glare rating of G2 or G3. You could mount these up to 8.75 m above grade on both sides of the plaza and comply with PC7 and light the plaza very well.

This might help you. The term “Lighting Boundary” shall mean the Property Lines that form the boundary of each lighting zone in the project, with the following exceptions:

When the property line abuts a public area that is a walkway, bike-way, plaza, or parking lot, the lighting boundary extends 5 feet (1,5m) beyond the property line.

The center of this plaza will have a 3 meter overlap between the two projects when you draw your lighting boundary. This is what I was using by lighting the plaza with a pole in the center. A two head pole with back side shieldingShielding is a nontechnical term that describes devices or techniques that are used as part of a luminaire or lamp to limit glare, light trespass, or sky glow.. But you're limited in wattage and manufacturer.

I meant the wall pack would have to be no more than 4.75 meters above grade.

Hi Bill,
Do you happen to know whether projects that have the older version of the LEED Online documents for this credit, meaning v3 should comply with the new requirements?

Maria,

You only need to comply with addenda published prior to your project registration date.

Look at the NCv2.2 version of this credit on this website. I had a dialog with someone about airport lighting. Post dated March 3, 2011.

You're easiest way to comply is to use PC7. But if you're good at persuasion you can attempt this credit as SSc8. Let us all know what works for you.

ER there's not that much special about lighting. Just really high levels under the canopy. This will need to be borrowed from elsewhere on the project site.

Thanks Bill. Both projects are only at pre-assessment/ scoping stage, but will definitely report back if we go forward with this credit.

Kit

We all have to follow ASHRAE 90.1. There's no additional wattage allowances beyond what is listed there.

I've looked for a definition of "temporary lighting" and can find none. I think they have intentionally left it vague. So that a holiday lighting scene is okay or a contruction jobsite is fine. It's probably one of those things where the more you try to define it the more complicated it gets. You'll just have to rely on common sense and hope the reviewer has the same opinion.

It's more likely to be considered temporary if it's only for 6 months. But if it's 6 months and occurs every year then it sounds more perminant.

Bill,
That's pure genius: "the more you try to define it, the more complicated it gets." Captures the inherent paradox of writing any code language!

David,
My goal is to take a complex subject and make it simple and obvious. Like a salad bar with tongs in three colors, Green, Yellow, and Red: to indicate what is healthy, what you should be cautious about, and what is unhealthy. People make decisions in fractions of a second a simple color system would be more helpful and less confusing then sheets printed with all of the calorie and fat numbers.

I'd love to boil this credit down to two lighting zones. Rural and Urban. And base urban on the US census definition by Zip Code. Then when the project enters it's Zip Code and the Regional Credits are automatically done, this Credit automatically tells you if it's considered Rural or Urban. No gray area, no charts and tables.

The site should already meet ASHRAE 90.1 wattage limits from EAp2. Indoor occupancy sensors should be required also per EAp2. The few people who work late are not that big of a deal are they? Or how many residences do the people walk around with shades open at night with their lights on?

Focus on uplight and glare. 0% uplight in Rural and ~5% uplight in Urban. Measure glare at the neighbors building or building setback line. Eye level aimed at the brightest source. Turn off site lighting in Rural areas during curfew hours.

But that's just my opinion.

Dormitories always seem to be an issue for this credit. There have been lots of other posts about compliance in dorms and the general trend is frustration that living spaces aren't exempt from the interior restrictions. Sorry.

You may still be asked to meet the site requirements. What if next year there is a new owner and the schedule is changed. Or they decide to turn on all the lights for a festival. Schedules are easy to change, more so than the installed lights.

You may be given some ease on site compliance documentation but there is no promise. It's all up to the LEED reviewer and if you convince them that the lights will always and forever be off between 6pm and 6am.

1) Any boundary that is next to a public right-of-way. It can sometimes be only one side of the project site.
2) I like your description but no. No rounded corners even if it makes sense to us. Let's say it's a city block with all of the buildings touching. The site boundary is the line between the walls. It extends straight out from the buildings to the street curb. It then follows the curb until it is even with the next property line and then goes straight back to the line between the walls. If there's a back alley it would be similar again.
3) No. Trees and other vegitation is considered temporary/seasonal and not counted for shading.

Thank you, Bill, for your answer.
It makes sense what you say and I'm affraid it should be that way. That doesn't realy help us...

I'm sorry but I don't understand. Can you rephrase. Or type in your native language and I'll try to translate.

I have long argued that the 0,01fc limit was unreasonable. But USGBC has been steadfast in saying projects must comply with this limit, even for emergency egress lighting.

You're not likely to comply. And good effort on playing with options to find a compliant path. Do you have "equals" on the bid documents? Different manufacturers have different house side shieldingShielding is a nontechnical term that describes devices or techniques that are used as part of a luminaire or lamp to limit glare, light trespass, or sky glow.. One might get a nice result.

Otherwise consider the Pilot Credit. There at least you can use the centerline of the road as the project boundary.

If you haven’t already, you should try a fixture with as house-side shield as Bill suggests. If that doesn’t work you might try moving you poles away from the edge into the middle of the lot and orienting the distribution towards the boundary to light into the spaces at the edge. May seem counterintuitive, but it could work - depends on how strict you are about meeting whatever your criteria have for minimum light levels at the edge of the lot.

Also note that the Pilot Credit 7 Option 2 does not have the 0.01 limit, just vertical illuminance limits at the lighting boundary. Your LZ2 limits would be 0.1 fc1. A footcandle (fc) is a measure of light falling on a given surface. One footcandle is defined as the quantity of light falling on a 1-square-foot area from a 1 candela light source at a distance of 1 foot (which equals 1 lumen per square foot). Footcandles can be measured both horizontally and vertically by a footcandle meter or light meter. 2. The non-metric measurement of lumens per square foot, one footcandle is the amount of light that is received one foot from a light source called a candela, which is based on the light output of a standardized candle. A common range for interior lighting is 10 to 100 footcandles, while exterior daytime levels can range from 100 to over 10,000 footcandles. Footcandles decrease with distance from the light source. The metric equivalent of a foot candle is 10.76 lux, or lumens per square meter. vertical on a plane at the lighting boundary up to the height of the highest fixture in the project. And as Bill points out, the boundary would be the centerline of the road – so it seems that you would easily comply. Warning though, if you do try to use the Pilot credit 7 there are still some funky things in the language (The Pilot credit it is the 2nd public review draft of the credit for LEED 2012) that may require some clarification.

You are encountering perhaps the biggest problem with the credit as written. Fortunately it will be fixed for LEED 2012 and the fix is available in the Pilot credit.

Many thanks to Bill and Glenn for your observations and suggestions. While we can reposition a number of fixtures, we will still be left with two that are simply not re-positionable. Also, the light fixtures are modeled with house side shieldingShielding is a nontechnical term that describes devices or techniques that are used as part of a luminaire or lamp to limit glare, light trespass, or sky glow.. We will take a look at the pilot credit as an alternative compliance path, but the frustration remains, especially when the municipal street lighting is considered.

You should only count the area that is illuminated by the facade lighting fixture. If you can see the light, or measure it, on the surface then it can be counted in the area calculation.

I've been getting this question a lot. ASHRAE 90.1 only relates to power usage. An exemption in 90.1 does not make the light fixture exempt from the spill light requirments of the rest of this Credit.

The proposed new version of this Credit will officially exempt city owned and operated lights.

Until then I recommend people to try and earn this credit and explain why you feel the lights should be excluded from the photometric calculations. Don't be suprised if you're denied.

You can also try Pilot Credit 7 if you have a spare ID credit available. This would let you exclude some government required lighting.

Great, thanks. I'm thinking we'll try excluding the parking lot lighting from the power density requirements in the template but deal with the photometrics for the whole boundary.

Great information. Thanks!

You wouldn't be able to claim the campus scenario since you'd need a single owner for the whole area being claimed and then you'd need to show the whole area is compliant.

Are the street lights owned by the county? You can try submitting the calculations without the street lights included and then note in your write-up that street lighting was provided under the scope of this work but they are not owned or operated by the project owner and therefore excluded from the lighting calculations. I have no idea how the reviewer will respond. Some may be very picky and flat out decline this. But this is how I would attempt this credit under this circumstance.

I've told others that it is an uphill battle trying to convince the reviewer that lights on the project shouldn't be included in the calculation. Just be warned.

The street lights are technically on private property but will be owned and maintained by the county through a utility easement. But the developer is required to install them as part of their scope of work. Unfortunately, we run across this problem on nearly every project as we have to include lights that we have no control over and must be located/designed to light areas outside of our project boundary as is typical in urban conditions. Seems like this credit discourages pursuit of dark sky initiatives in urban areas, which is unfortunate, as these areas generally have the worst light pollution.
Anyway, thanks for your response, we will certainly try to submit excluding these lights, but won't count on it.

Good question. I don't know. I usually assume the final product is what determines the lighting zone. I kinda wish it would be based on neighbor's classification but that can create other problems. Just go for LZ2, you should be fine. It's a very large project.